_____ _____: governs gas diffusion through alveoli. It's rate is directly proportional to the tissue area, a diffusion constant (solubility, molecular wt), and the pressure differential on either side of the membrane.

Fick's Law

True or False: Co2 diffuses about 10 times faster than O2 because of higher solubility.

Actin and myosin binding cause myosin ATPase to hydrolyze ___ to ADP causing myosin crossbridge movement.
Ca2+ is taken up by the _____ _____ as muscle activation ceases, restoring Troponin-Tropomyosin inhibition with actin and myosin in relaxed state.

Ca2+

ATP

Sarcoplasmic reticulum

_____: fibers run parallel to muscle's long axis, a fiber's force generation transmits directly to the tendon.
_____: pennation angle, some of the force is Not transmitted to the tendon, but allows for more sarcomeres to contribute to force production.

Fusiform

Pennate

Afferent neurons enter cord through ____ ____ and transmit sensory information from periphery.
Afferent neurons synapse through _______ that relay information to various levels of cord.

dorsal root

interneurons

____ ____: consists of the motor neuron and all the muscle fibers it innervates. May innervate many muscles but each muscle fiber is innervatied my only one neuron.

motor unit

The ____ _____ is the information sender and the _____ _____ is the information recipient. However, most neurons function as both.

Presynaptic neuron

postsynaptic neuron

At an excitatory synapse, ___ binds to postsynaptic neuron and causes _____ channels to open. The influx of ____ increases the voltage across the membrane and an action potential is generated if reaches approximately ___.

At an inhibitory synapse the binding of neurotransmitter ____ to postsynaptic neuron causes ___ channels to open. Influx of ____ decreases the voltage across the membrane and an action potential is not generated.

GABA

Chloride

Cl-

_____ _____: one of the factors that contributes to increases in strength prior to hypertrophy of the muscle.